This study will evaluate the cost-effectiveness of lung cancer screening in HIV infected (HIV+) persons. Candidate: The primary objective of this application is to support Dr. Keith Sigel's career development into an independent investigator in the field of HIV-associated malignancies. Dr. Sigel's career goal is to improve cancer prevention in HIV+ persons by evaluating the unique harms, benefits and costs associated with cancer screening in this population. His proposed training plan focuses on 3 areas: (1) Cohort Study Design; (2) Decision Analysis; and (3) Cost-effectiveness Analysis. Environment: Mount Sinai is a national leader in research and is one of the top 20 medical schools in NIH funding. It is the largest academic provider of HIV care in New York and has one of the largest lung cancer screening research programs in the world. Research: Cancers are emerging as the leading cause of death in HIV+ persons, and lung cancer accounts for the majority of these deaths. Furthermore, HIV+ persons have more than twice the risk of lung cancer of HIV- persons. Lung cancer screening with low dose computed tomography (LDCT) has demonstrated a considerable mortality benefit among HIV- heavy smokers. An increased risk of lung cancer and a high rate of smoking (>70%) suggests that the HIV+ population is an important high-risk group to target for lung cancer screening. However, frequent prior lung infections in HIV+ persons may cause more false positive screening tests (which may lead to invasive procedures with significant complications). Thus, the harms, benefits and costs associated with lung cancer screening in HIV- persons may be different in HIV+ persons. Therefore, our aims are to: (1) determine the rate of positive screening LDCTs and subsequent clinical evaluations in HIV+ smokers and compare to a similar cohort of previously screened HIV- smokers; (2) estimate harms and benefits of annual LDCT lung cancer screening in HIV+ smokers using a simulation model; and (3) determine the lifetime costs and evaluate the cost-effectiveness of annual LDCT cancer screening vs. usual care in HIV+ smokers. We will conduct a prospective study assessing LDCT screening findings in a cohort of HIV+ smokers, comparing findings to matched HIV- controls from an existing screening study. Using these and other data, we will create a simulation model of lung cancer screening in HIV+ patients. We will then measure costs associated with screening in HIV+ persons to incorporate into our model, providing cost-effectiveness estimates of LDCT screening in HIV+ individuals.